1. Field of the Invention
The present invention relates to an optical recording apparatus and method, and more particularly to an apparatus and method for driving a laser diode (LD) for recording data on an optical disk.
2. Background of the Related Art
The Orange Book for describing specifications for a variety of recording disks such as a CD-Recordable (CD-R) disk has typically adapted two recording methods for recording arbitrary data on the CD-R disk. The two recording methods are a Mode 1 (also called an Orange 1) and a Mode 2 (also called an Orange 2), which will hereinafter be described in detail. The Mode 1 (i.e., Orange 1) is defined as a recording method for use with overpower in consideration of medium characteristics of the CD-R disk. When an LD of an optical pick-up device is driven for a recording period of time, a prescribed delay time occurs in a signal's rising edge because of characteristics of the LD, and a recording pit of a desired size is not formed at a desired time. The Mode 1 applies overpower at a prescribed time at which a recording power is turned on. In more detail, because the Mode 1 applies an LD driving signal shown in FIG. 1 to an LD of such an optical pick-up device, a signal's rising edge is quickly formed in the waveform of a real LD driving signal, which results in no delay time in such a signal's rising edge.
The Mode 1 for use with such overpower has an advantage in that it allows a signal's rising time to be faster and thereby correctly and stably forms initial recording pits. However, the Mode 1 has a disadvantage in that it must set up many variables to generate such an LD driving signal with the overpower. In this case, the variables can include time variables Td, Tf and Tw for generating driving pulses PEO and LDH, and other variables VWDC1 and VWDC2, besides a VRDC being a driving voltage.
Therefore, in order to adapt the Mode 1, the variables corresponding to individual recording pits 3T˜11T for every disk manufacturer (i.e., every disk code) should be detected and stored in a memory. The time variables Td, Tf and Tw are different for every disk manufacturer and every recording pit. Accordingly, a large amount of work and a long time have been wasted to detect variables and store them in a memory.
The Mode 2 (i.e., Orange 2) forms recording pits by applying a driving signal having no overpower (e.g., an LD driving signal shown in FIG. 4) to an LD of an optical pick-up device. The Mode 2 need not set up a variable VWDC2, but needs to set up other variables Td, Tf, VRDC and VWDC1.
The Mode 2 has an advantage in that it takes much less work and less time than the Mode 1. However, the Mode 2 has a disadvantage in that it does not correctly form initial recording pits because a prescribed delay time occurs in a signal's rising time because of LD's characteristics, which results in deterioration of the quality of recording marks. Such deterioration of the quality of recording marks becomes serious in a high-speed recording time.
The above references are incorporated by reference herein where appropriate for appropriate teachings of additional or alternative details, features and/or technical background.